Surface functionalization of coconut fibers by enzymatic biografting of syringaldehyde for the development of biocomposites

In the present work, laccase from Trametes versicolor has been used for the biografting of natural phenol syringaldehyde (SA) on the surface of coconut fibers. Three parameters such as concentration of laccase, phenol and incubation period have been varied to optimize the reaction conditions for maximum biografting. Biografted coconut fibers were characterized with FTIR, SEM, and XRD techniques. Thermal, antibacterial and hydrophobic properties were analyzed by thermogravimetric analysis (TGA), colony forming unit (CFU) and moisture retention methods, respectively. An enhancement in the properties of coconut fibers was observed after biografting of SA. Modified coconut fibers were used as a reinforcement in the poly(butylene succinate) matrix to prepare biocomposites. Mechanical properties (tensile and flexural strength) of the biocomposites were evaluated by a universal testing machine. An increase in the mechanical strength of biocomposites was observed when reinforced with biografted fibers in comparison to unmodified coconut fibers. The fractured surface morphology of the composites indicated the better interlocking of the biografted fibers with the polymer matrix.